1. Field of the Invention
This invention relates in general to wheeled vehicles such as bicycles. In particular, this invention relates to an apparatus and the method of attaching a hollow axle wheel to a wheel mount wherein the wheel can be removed easily without the use of tools by operations on only one side of the wheel hub but will not unexpectedly separate from the wheel mounts.
2. Description of Prior Art
Most better-quality bicycles on the market are equipped with quick release front (and sometimes rear) wheels. These bicycles use a standard method of avoiding unwanted separation of the front wheel comprising a recessed wheel mount (or dropout), or small tabs which retains the wheel skewer at both ends, and thus the wheel, even when the quick release cam has been loosened. As used herein, the term “skewer” or “wheel skewer” is also known in the industry as a “spindle”, “draw bar”, connecting rod”, control shaft” and “retaining rod”.
On bicycles currently on the market, the skewer is mounted concentrically inside a hollow hub axle and is equipped with a quick release cam on one end, and an adjusting threaded nut on the other end. The skewer assembly is kept centered laterally in the wheel hub by two conical springs, one on each side, which push outward opposing each other, one on the quick release cam and the other on the nut. The quick release cam, when locked, pulls the skewer outward thereby pushing inward against the dropout as well as causing the distal nut to push inward on the opposite dropout.
In this way, the dropouts are clamped between the quick release cam and the hub on one side of the hub, and between the nut and the hub on the other side of the hub. The dropouts on most bicycles are equipped with either raised tabs, or in many cases, the surfaces upon which the quick release and the nut push are recessed below the rest of the dropout surface. The single process of opening the quick release cam does not produce enough “throw” to allow the quick release and the nut to clear the recess or tabs to exit from the dropout. Therefore, while holding the quick release with one hand, the nut must be further unscrewed from the threaded skewer before the wheel can be removed from the dropouts. In this way, unexpected separation of the front wheel is usually avoided.
However, when the wheel is re-inserted into the dropouts, the adjusting nut remains unscrewed and the wheel, while looking like it is attached to the bicycle or other wheeled vehicle, is not. In this “dangerous state” condition the bicycle is extremely dangerous as it appears to be rideable, but the front wheel can easily separate from the wheel fork. Only a close look at the condition of the quick release and nut will tell the rider that the wheel has not been secured for riding.
In short, the system used on current bicycles relies on the rider to remember to screw on the adjusting nut, and then lock the quick release. In addition, in order to do this, the rider must hold the bicycle up with one hand, hold the quick release on one side of the bicycle with another hand, and turn the adjusting nut on the opposite side of the bicycle with yet another hand—making the process of safely fastening a wheel difficult at best for the average rider with only two hands. Furthermore, the process of adjusting the nut to the correct tension such that the quick release cam operates properly is found to be challenging by many riders.
Several attempts have been made to solve some of these problems, however, none have yielded a satisfactory solution to both avoiding the “dangerous state” as well as making the process easy with only two hands.
Many recent attempts have been made to provide a system which does not require the adjustment of the adjustable nut to the correct tension for proper quick release cam locking (see U.S. Pat. Nos. 6,260,931 {Stewart}, 6,241,322 {Phillips}, 5,961,186 {Phillips}, 5,673,925 {Stewart}, 5,653,512 {Phillips}, and 5,121,973 {Phillips}.). The '973 patent has a primary locking device operated from one side of the wheel.
U.S. Pat. No. 6,260,931 (Stewart) discloses a quick release bicycle wheel wherein the quick release cam lever is spring loaded urging it to the closed position. If it is assumed that the adjusting nut is not unscrewed too far, this device solves the problem of avoiding the “dangerous state”. However, in order to install the wheel on the bicycle, the operator must hold the bicycle with one hand, hold the quick release lever engaged with another hand, and insert the wheel with a third hand which could prove to be difficult for the average rider. It is possible that the rider, absent any instructions, might unscrew the adjusting nut in order to install the wheel on the fork and then use the quick release lever as a “wing nut” handle.
U.S. Pat. No. 6,241,322 (Phillips) discloses a quick release bicycle wheel wherein the installation of the wheel to the wheel fork is made slightly easier by fixing the distance the adjustable nut must be tightened in order for correct quick release cam fastening. However, this device does not avoid the “dangerous state” condition, nor does it prevent the nut from being loosened too far and falling off the skewer.
U.S. Pat. No. 6,089,675 (Schlanger) discloses an invention wherein the wheel is attached to a more traditional slot on one dropout and a threaded hole on the other dropout. The Axle/skewer comprises a large knob on one end and a threaded area on the other end. This system also does not avoid the “dangerous state” wherein the wheel could appear to be mounted to the wheel fork for riding however the wheel is not secured.
U.S. Pat. No. 5,961,186 (Phillips), U.S. Pat. No. 5,673,925 (Stewart), and U.S. Pat. No. 5,653,512 (Phillips) all disclose essentially the same concept of an expanding nut on the opposite side of the axle skewer from the quick release cam. This nut reduces in width either by rotation or by a push/pull action taken by the rider thereby allowing the nut and the opposite side quick release to clear the safety tabs and the wheel to be removed. These three devices all require the rider to unlock the quick release cam on one side of the wheel, then move to the other side of the wheel to reduce the width of the opposite nut.
Various other efforts have been made to design a system that would allow the easy removal of a bicycle wheel while making sure it did not detach unexpectedly. None have provided both ease of use and absolute safety. For example, U.S. Pat. No. 5,576,020 defines an approach, using manually operated primary and secondary locking devices where operation on both sides of the wheel occurs to effectuate both attachment and detachment.